International Agency for Research on Cancer (IARC) - Summaries & Evaluations

PIPERONYL BUTOXIDE

5. Summary of Data Reported and Evaluation

5.1 Experimental data

Piperonyl butoxide was tested for carcinogenicity in two studies
in rats and in three studies in mice by oral administration. It was
also tested in mice of three strains by subcutaneous administration
(in one, neonatally). No statistically significant incidence of
tumours was observed in mice or rats.

Treatment of rats with high doses of piperonyl butoxide during
organogenesis did not affect foetal development; however, its
continued administration at high dose levels for three generations
caused reduction in the number of pregnancies and offspring.

Piperonyl butoxide has been reported to be nonmutagenic to
bacteria, silkworms and cultured mammalian cells. A dominant lethal
study in mice was inconclusive. Lack of availability to the Group of
much of the detailed data prevented overall evaluation of the
mutagenicity of piperonyl butoxide, but all cited results have been
negative.

5.2 Human data

Piperonyl butoxide was developed in 1947. Its production,
formulation and use as an insecticide synergist in a variety of
nonagricultural and agricultural applications are potential sources of
exposure, both of workers and of the general population.

The available data were insufficient to evaluate the
teratogenicity of piperonyl butoxide to humans. No data were
available to evaluate its chromosomal effects in humans.

No case report or epidemiological study of the carcinogenicity of
piperonyl butoxide alone was available to the Working Group. (See
also the section 'Cancer Epidemiology of Pesticide Manufacturers,
Formulators and Users', in this volume.)

5.3 Evaluation

The available data do not provide evidence that piperonyl
butoxide is carcinogenic to experimental animals. No data on humans
were available.

The available data provide no evidence that piperonyl butoxide is
likely to present a carcinogenic risk to humans.